1. Field of the Invention
The invention relates to building construction, and particularly to an open/fold-up truss used in building construction.
2. Background
Due to the competitive nature of the building industry and the increased cost of labor and materials, it has become necessary to reduce on-site labor by increasing the use of preassembled building components. Accordingly, various preassembled truss structures have been devised to reduce the cost of labor and thereby become more competitive.
Preassembled truss structures generally fall within one of three categories: (1) rigid; (2) knock-down; and (3) open/fold-up. Examples of the rigid type of truss structure are disclosed in Helfman, U.S. Pat. No. 4,437,273 and Tuomi, U.S. Pat. No. 4,005,556. The rigid type of truss structure is completely preassemble prior to shipping such that the individual frames are erected without any on-site assembly. Accordingly since the frames are essentially shipped in their erected state transportation becomes a significant problem. Therfore, to obviate this problem, the knock-down and open/fold-up type truss structures have been devised to limit the overall shipping dimensions of the truss structure.
Examples of knock-down type truss structures are disclosed in Sanford, U.S. Pat. No. 4,167,090; Wright, U.S. Pat. No. 3,662,502; Fuller, U.S. Pat. No. 4,096,670; and Kandel, U.S. Pat. No. 4,294,050. The knock-down type truss is partially assembled prior to shipping to include individual truss structures such as, for instance, a roof truss and a floor truss. After being transported to the job site, the individual truss structures (i.e., the roof truss and the floor truss) are then assembled to form the completed truss structure. While these knock-down type trusses reduce the problem associated with their transportation they require substantial on-site labor to connect the separate portions of the complete truss structure to form a single structure.
The open/fold-up type truss structure reduces the transportation problem without requiring the on-site labor associated with the knock-down truss. The open/fold-up type truss structure is preassembled and shipped in a collapsed state. Once on the building site, the truss structure is then unfolded and secured in an erected position. Examples of open/fold-up trusses are disclosed in Mankowski, U.S. Pat. No. 4,555,889; Solesbee U.S. Pat. No. 3,605,355; Perry, U.S. Pat. No. 3,701,225; McElhone, U.S. Pat. No. 2,642,825; and Osborne, U.S. Pat. No. 4,242,845.
Mankowski teaches a collapsible wall stud. Solesbee and Perry disclose a collapsible roof assembly. McElhone teaches a foldable roof truss which includes stud supports. Finally, Osborne discloses a hinge arrangement to which wall panels are attached and swung into position as the roof panel is raised. As can be seen, these arrangement are directed solely to roof trusses and stud supports thereby limiting the extent to which open/fold-up type trusses can be utilized. It is to an improved open/fold-up type truss structure to which the subject invention is directed. The profile open/fold-up truss, hereinafter referred to as POP truss, of the present invention overcomes the aforementioned disadvantages associated with the prior art trusses.